/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMeshAttributeSet.h
Enable the matching attributes and overlay layers as the ToMatch set, but do not copy any data across. If bClearExisting=true, all existing attributes are cleared, so after the function there is an exact match but any existing attribute data is lost (!) If bClearExisting=false, new attributes are added, but existing attributes and data are preserved If bDiscardExtraAttributes=true and bClearExisting=false, then attributes in the current set but not in ToMatch are discarded, but existing attributes are not cleared/reset
void EnableMatchingAttributes ( const [FDynamicMeshAttributeSet](API\Runtime\GeometryCore\DynamicMesh\FDynamicMeshAttributeSet) & ToMatch, bool bClearExisting, bool bDiscardExtraAttributes )